Pancreatic ducts of the rat and hamster will be isolated and cultured eight weeks in an agarose matrix in CMRL-1066 supplemented with fetal bovine serum, insulin, and dexamethasone. The ducts will be exposed to N-nitroso-bis (2-oxopropyl) amine (BOP) in an effort to cause morphological changes similar to those seen in the pancreas in vivo. The effects of these carcinogens will be potentiated by prior injection of hamsters with inducers of pancreatic mixed function oxidases and/or inclusion in the culture medium of growth promoting hormones such as epidermal growth factor or tumor promoters such as the phorbol ester TPA. Pancreatic ducts will be isolated from hamsters injected with BOP and further changes in these ducts will be monitored in culture. The effects of the carcinogens will be monitored morphologically by light and electron microscopy, biochemically by enzyme assays and SDS-polyacrylamide gel electrophoresis, biologically by assessing the ability of the treated cells to form colonies in soft agar and to grow in a host animal, and immunologically by assessing changes in fluorescent lectin binding and in antigens as detected with anti-duct antiserum raised in guinea pigs.